ask her nicely to go **** at his place instead of yours, dont talk to her anymore or at least keep it to a minimum (no small talk, just business. avoid her at all cost), go to the gym and vent your frustrations/anger/sadness there. get on the treadmill/park/track and run, physically and mentally. leave all the sadness behind, like forrest gump did. it worked for me. now im toned, healthy and over her.